Compensated displacement meter



Jan. 25, 1944. D. A. SILLERS I 2,339,956

COMPENSATED DISPLACEMENT METER Filed Jan. 19, 1942 I fi 3/ zig lu L 3 IDONALD As &5

BY cit/ aw $7 7' TOR/v5 V.

Patented Jan. 25, 1944 I 1-'J f i3 6' oomrnNsn'tcnn DISPLACEMENT METERYSillers, l ne's, (res.

Application January'lgl, 1942, SerialNo. 427,283

. This invention relates to fluid meterk'fand" more particularly to thedisplacement type meter in which means is provided for automatictemperature compensation so that indications by the Tis c ai s. f.

meterrepresent the rate of flow or the quantity 5- o of fluid whenreduced to a standard or a predetermined temperature. 1 j Influid meterssuch as are usually utilized'in the measurement of gaseous fluids, forexample,'f gas meters, displacement chambers with recip 1 rocatingdiaphragms are providedjand, through suitable valving means, theadmission-[to and exhaust from the receiving chambers is' con 'jtrolled. Such control of the fluid to be measured is utilized to efiectmovement of niechanisms' 'ls including a tangent or crank arm to, inturn, im-"f part movement to an indicating or; recording; mechanism sothat the rate of flow-or the quanf tity f fluid passing through themeter in a given length of time is indicated. Howeverythe 2 fluid to bemeasured expands or contracts with change in temperature at the locationoffthe. meter and hence mere volumetric measurement does not accuratelyindicate the standard volume of the fluid at a given temperature passing2 through the meter. This is particularly impore} tant in meters formeasuring gaseous fluids, such as illuminating gas, wherein the'volume'indicated is too large in hot weather and is too small in-"cold weather.The primary object of the invention is to' ob viate the indicateddifficulties in a simple efiective manner. f

Another object is to provide athermostat which controls the effectivelength of the tangent "3 orcrank arm which controls thevolume'tricdisplacement resulting from the reciprocating I movements ofthe diaphragms. Still another object is to provide'a'constructionwhereby the variations in the lengthof the 6 crank arm is effectedrectilinearly relative to the; center of the crank or valve shaft.Suchoperation is desirable since any change in lead [01f lag offthecrank arm relative to the shaft results in the-change in proof oraccuracy of the meter.

Still another object is to provide a device jof' the class describedwhich is unafiected by Chang in pressure in the fluid being measured. [jThe foregoing objects are primary.'objects and will, together withother'objects, be more fully} apparent from the following descriptionof; the embodiment of the invention consid'ered'in' confnection with theaccompanying drawing which:

Fig.- 1 is a plan view of a meter embodying the" 35 invention, the coverof the meter being removed to expose the mechanism embodying theinvention: I.

Fig52 is "a plan view of the thermostatic unit r'crank arm comprising anelement of the invention; v

Fig; 3'is an elevational view of the me shown inFig. 2;

M Fig. fl isfa plan view similar to that shown in o' Fig'l- 2; 'butshowing the configuration of the thermostatic element when subjected toan elevated temperature.

Referring-to the drawing, there is shown at l afmetenhousing providedwith openings 2 and 3 s'o that the meter may be connected in a pipelineinw'hich the flow of fluid is to be measured. The-housing l enclosesdisplacement chambers for receivingand exhausting quantities of the.fluid to be measured, as is well known in the art, 0 and the encloseddisplacement mechanism operates to produce partial turning movement ofthe rods 4 and 5 which extend outwardly from within the displacementchambers, and which control the movements of the diaphragms in the dis-5 placement chambers.

"The rods 4 and 5 have arms 6 attached to their outer endsandthese armsare connected to the crank---means, generally identified as I0, by

chanism ,s means-of links H so that the turning movement 30 of the rods4 and 5 produces rotation of the crank-means 10 to rotate the crank orvalve-- shaft which operates the valves beneath the valve -cover l3whereby the action of the displacement mechanism is controlled. Theshaftl2 also -carries a worm l5 meshing with the worm wheel- IIS mountedon the shaft 17 to operate the indicator mechanism l8 which is visiblethrough a window H! on the exterior of thehousing to indicate the rateof flow through the meter-orthe total quantity of fluidpassingtherethrough -in a given period of time. 4 The crank assembly IE1is of special construc 3 tion and comprises (Fig. 2) a collar to which...,is,.attached the pivot 26 passing through the 245"v inner-ends ofthe links I I. An opening 21 transverselyof the collar 25 receives thepost 28 fixed upon and extending outwardly from the block 29. The collar25.is held in fixed axial position upon .-the;post-;28-; by means ofnuts 30 whereby such position maybe suitably selected for the par.--

ticular fluid being measured and also to com-- pensate for; thetemperature responsive characteristics; of the particularthermo-res'ponsive .assembly usedp These ports 25, 28 and 29 may betermed a crank member.

It is to be noted that the collar 25 is provided with threaded alignedopenings in opposite sides thereof to receive cap screws 3| so that thepost 28 can be adjusted transversely of the collar.

Attached to the block 29, as by means of rivets 35, and to a similarblock or crank member 38 fixed upon the shaft I2, are one or moreU-shaped bimetallic thermo-responsive elements 31, which are unafiectedby changes in the pressure of the fluid being measured. Each of theseelements may comprise an innrand an outer. strip terial having differentcoeificients of therma pansion and are so constructed as to have thegeneral shape shown in Figs. 1 and 2 when at a given temperature as, forexample, 69 Eahrep; heit, which is a standard temperature for meas;urement of gas for domestic consumption; With a metal of higherthermo-expansion on side, the unit tends to expand with increase intemperature and hence move the block 29 to alter the crank length sothat proper. comp eri sation is efiectecll The constructionfjust:generally described operates satisfactorily where small; temperaturechanges are involved. It is; tg{be note'dghowever, that expansionandcontractipu from the positions shown in Figs. 1' and 2 ten t9 causethe riveted ends of the elements Q1; t be subjected to bending action.Such b'endin tion or flexure causes the inherent stifin s t elements3'I'to affect the length of the crankar The efiect just ind icat ed isof. little cp rj slgueng for small temperature ranges.

I order t P ov eyi l z t llq srate more satisfactorily for largetemperature; ranges, I Prefer t he hemesp ns ve. d merits '5 h l'b eerqu'n lat t a intelflmath t9. vli iwa 'f fivnithg nt fil g i er;

i l'ae smh afid li Strip of" hfil ermei; 32;. p ns nfiz s aced n he oude.

Th u e o U- p r he. deme its.

om se a t oi w mal, e n lonfiit p aced r e t id and t p-o h gh malexpansion 45 is placed on theinsid ei The thermo-responsive couplesformedin this map e are suitably secured togetherat points 49; as y.

e in or w ld ng to form posite ele which tendtoflex in the manner categin Fig. l of the drawing, This constru iomh een o nd. to. e ate. e

radially of the shaft I2 the desired amount fer, any given changeintemperature. Torque for the rotationof the shaft; llmay be transmittedthrough the. thermQ-expansive, as; sembly Hi, This, assembly can,however, be re lieved of this function by providing. the,g uide,,

member Adattached to the shaft l2 andextend to the, arms. I l.

Inthe operation of the described embodiment. of the, invention it isassumed that the. collairi 25z Willbe properly adjusted axially. of thepost 28 by meansof the nuts 30 and that proper locationof the posttransversely of the collar will be brought about by adjustment of thecap screws-{31 so that the thermo-responsive assembly-will haye the.general shape shown in Figs. 1' and 2 atta given temperature such as 60Fahrenheit Pas;

sage'of fluid through the metercause's th rods dr .1 NgF QQt QKX;@QQQQYQnQE P-QZ as l! lemai a. id an of e er tur s at hamcm. I: lar. ia ta dothe p vot 1 11 6 mqvsst eses ee W1 m 5 interiorly of the housing I willbe brought about.

An increase in temperature will result in the increase in the effectivelength of the crank assembly to control the reciprocating movements 'ofthe diaphragms in the displacement meters so 1 a ve snletrie lacemen inh different 915 the meter will; be increased in proper proportion andalso that the indication by the indicator l8 will be corrected for astandard temperature regardless of the actual temperature of lg, themeasured. Attention is directed tg the :Qactthat the present device isunaffected by changesin pressure of the fluid being metered, EQQQQX"ififig uishes it from the Bourdon type of temperature responsiveelement. It is to 20 beunderstood, however, that the invention may belit ll-a nt types, o mete without th V. ittfid; r u h. he. leg. ihermostati s rips. lzete ee b a sa o. ma med T q hare m e i Bat in by Q%n 1s l .efieaa I a i a iml rz he dista cebee d p t 2 does notdirectly-slow;

.1a. e meet ut do o, indisht W12 m ter wherein.

Q; displacement is controlled by therotation of; a

h qmlal athe ep e r na a; piv t mora ghan smo h h lmetea. a crankassembly including a crank; membermounted 0 3 a ,l- R 'Q la e end; rankmember h sme ma; diurtablrmqv 1 he. th r member; her r sage a e t rc nneme. said: members and operableto move the pivptradiallyr h h l emrsnsete2a en th h nle at r l e nses. n a.

i haft andslidablr .81 5? Par que. rom; he; i ot;

me; w to th ,hatts r dius ab e. ne r nk. ssgm lys 6 5 for t meterswherein the length oi the automaticallyadjustable as;a

j turned by the crank asserr be moved by; the displacement i eeti a .h'sg ifi ameter an -4a r kl ssem lnshaft and pivot comprising a connectedto each of said support blocks, whereby changes in temperature vary thespan of the open ends of the U elements to vary the length of the crankassembly.

3. A thermo-adjustable type crank assembly for displacement meterswherein the length of the crank is to be automatically adjustable as afunction of the existent temperature comprising a crank shaft to beturned by the crank assembly, a pivot pin to be moved by thedisplacement mechanism of the meter, and a crank assembly connectingsaid shaft and pivot comprising, a support block on the shaft, a supportblock connected to the pivot, and a pair of bimetallic U shapedthermo-responsive elements opposed to each other and having one end ofeach element connected to each of said support blocks, whereby changesin temperature vary the span of the open ends of the U elements to varythe length of the crank assembly, each of said elements being composedof two compounded strips, each strip being made up of three pieces, oneof which is of difierent thermo-responsive characteristics than theothers.

4. A thermo-adjustable type crank assembly for displacement meterswherein the length of the crank is to be automatically adjustable as afunction of the existent temperature comprising a crank shaft to beturned by the crank assembly, a pivot pin to be moved by thedisplacement mechanism of the meter, and a crank assembly connectingsaid shaft and pivot comprising, a support block on the shaft, a supportblock connected to the pivot, and a pair of bimetallic U shapedthermo-responsive elements opposed to each other and having one end ofeach element connected to each of said support blocks, whereby changesin temperature vary the span of the open ends of the U elements to varythe length of the crank assembly, said block connected to the pivotincluding a post and an adjustable collar thereon.

5. A thermo-adjustable type crank assembly for displacement meterswherein the length of the crank is to be automatically adjustable as afunction of the existent temperature comprising a crank shaft to beturned by the crank assembly, a pivot pin to be moved by thedisplacement mechanism of the meter, and a crank assembly connectingsaid shaft and pivot comprising, a support block on the shaft, a supportblock connected to the pivot, a pair of bimetallic U shapedthermo-responsive elements opposed to each other and having one end ofeach element connected to each of said support blocks, whereby changesin temperature vary the span of the open ends of the U elements to varythe length of the crank assembly, and a guide arm fixed on said shaftand bearing against said pivot.

DONALD A. SILLERS'.

